export class Crc32 {
    private static readonly lookUp: Uint32Array = new Uint32Array([
        0, 1996959894, 3993919788, 2567524794, 124634137, 1886057615,
        3915621685, 2657392035, 249268274, 2044508324, 3772115230,
        2547177864, 162941995, 2125561021, 3887607047, 2428444049,
        498536548, 1789927666, 4089016648, 2227061214, 450548861,
        1843258603, 4107580753, 2211677639, 325883990, 1684777152,
        4251122042, 2321926636, 335633487, 1661365465, 4195302755,
        2366115317, 997073096, 1281953886, 3579855332, 2724688242,
        1006888145, 1258607687, 3524101629, 2768942443, 901097722,
        1119000684, 3686517206, 2898065728, 853044451, 1172266101,
        3705015759, 2882616665, 651767980, 1373503546, 3369554304,
        3218104598, 565507253, 1454621731, 3485111705, 3099436303,
        671266974, 1594198024, 3322730930, 2970347812, 795835527,
        1483230225, 3244367275, 3060149565, 1994146192, 31158534,
        2563907772, 4023717930, 1907459465, 112637215, 2680153253,
        3904427059, 2013776290, 251722036, 2517215374, 3775830040,
        2137656763, 141376813, 2439277719, 3865271297, 1802195444,
        476864866, 2238001368, 4066508878, 1812370925, 453092731,
        2181625025, 4111451223, 1706088902, 314042704, 2344532202,
        4240017532, 1658658271, 366619977, 2362670323, 4224994405,
        1303535960, 984961486, 2747007092, 3569037538, 1256170817,
        1037604311, 2765210733, 3554079995, 1131014506, 879679996,
        2909243462, 3663771856, 1141124467, 855842277, 2852801631,
        3708648649, 1342533948, 654459306, 3188396048, 3373015174,
        1466479909, 544179635, 3110523913, 3462522015, 1591671054,
        702138776, 2966460450, 3352799412, 1504918807, 783551873,
        3082640443, 3233442989, 3988292384, 2596254646, 62317068,
        1957810842, 3939845945, 2647816111, 81470997, 1943803523,
        3814918930, 2489596804, 225274430, 2053790376, 3826175755,
        2466906013, 167816743, 2097651377, 4027552580, 2265490386,
        503444072, 1762050814, 4150417245, 2154129355, 426522225,
        1852507879, 4275313526, 2312317920, 282753626, 1742555852,
        4189708143, 2394877945, 397917763, 1622183637, 3604390888,
        2714866558, 953729732, 1340076626, 3518719985, 2797360999,
        1068828381, 1219638859, 3624741850, 2936675148, 906185462,
        1090812512, 3747672003, 2825379669, 829329135, 1181335161,
        3412177804, 3160834842, 628085408, 1382605366, 3423369109,
        3138078467, 570562233, 1426400815, 3317316542, 2998733608,
        733239954, 1555261956, 3268935591, 3050360625, 752459403,
        1541320221, 2607071920, 3965973030, 1969922972, 40735498,
        2617837225, 3943577151, 1913087877, 83908371, 2512341634,
        3803740692, 2075208622, 213261112, 2463272603, 3855990285,
        2094854071, 198958881, 2262029012, 4057260610, 1759359992,
        534414190, 2176718541, 4139329115, 1873836001, 414664567,
        2282248934, 4279200368, 1711684554, 285281116, 2405801727,
        4167216745, 1634467795, 376229701, 2685067896, 3608007406,
        1308918612, 956543938, 2808555105, 3495958263, 1231636301,
        1047427035, 2932959818, 3654703836, 1088359270, 936918000,
        2847714899, 3736837829, 1202900863, 817233897, 3183342108,
        3401237130, 1404277552, 615818150, 3134207493, 3453421203,
        1423857449, 601450431, 3009837614, 3294710456, 1567103746,
        711928724, 3020668471, 3272380065, 1510334235, 755167117,
    ]);

    private crc: number;
    private readonly initialCrcValue: number; // Renamed from polynomal for clarity

    constructor(initialValue: number = 0xFFFFFFFF) {
        this.initialCrcValue = initialValue;
        this.crc = initialValue;
    }

    public static calculateCrc(data: Uint8Array, initialValue: number = 0xFFFFFFFF): number {
        let currentCrc = initialValue;
        for (let i = 0; i < data.length; i++) {
            currentCrc = ((currentCrc >>> 8) ^ Crc32.lookUp[(currentCrc & 0xFF) ^ data[i]]) >>> 0;
        }
        return (currentCrc ^ initialValue) >>> 0;
    }

    public append(data: Uint8Array): void {
        for (let i = 0; i < data.length; i++) {
            this.crc = ((this.crc >>> 8) ^ Crc32.lookUp[(this.crc & 0xFF) ^ data[i]]) >>> 0;
        }
    }

    public get(): number {
        return (this.crc ^ this.initialCrcValue) >>> 0;
    }
} 